CORTEX Basic Science

Question 1

benign bone tumour:

a bony spur, originating the in metaphyseal regions of long bones, growing away from the epiphysis.

Answer 1

osteochondroma

Question 2

benign bone tumour:

A mostly lucent lesion, with a patchy sclerosis, found within the metaphyseal region of long bones.

Answer 2

enchondroma

Question 3

benign bone tumour:

A lucent, multi-loculated cyst found within the medulla of many different bones, often with associated cortical expansion.

Answer 3

aneurysmal bone cyst

Question 4

what is the name of the layer of thin connective tissue that surrounds individual muscle fibres?

Answer 4

endomysium

The connective tissue that surrounds the muscle as a whole is called the epimysium, the connective tissue around a single fascicle is the perimysium and the connetive tissue around a single muscle fibre is the endomysium.

Question 5

what are the risk factors for avascular necrosis?

Answer 5

excess alcohol intake
illicit steroid use
regular, prescribed prednisolone use

Question 6

malignant bone tumour:

A malignant tumour of endothelial cells in the marrow. Most cases occur between the ages of 10 and 20. It may be associated with fever, raised inflammatory markers and a warm swelling and may be misdiagnosed as osteomyelitis.

Answer 6

Ewing’s sarcoma

Question 7

malignant bone tumour:

A malignant primary bone tumour which tends to occur in abnormal bone (bone infarct, fibrous dysplasia, post irradiation, Paget’s disease), most commonly in adolescents or young adults.

Answer 7

fibrosarcoma

Question 8

malignant bone tumour:

The most common form of primary bone tumour, producing abnormal bone. Most cases are seen in younger age groups (adolescence and early adulthood) with 60% involving the bones around the knee.

Answer 8

osteosarcoma

Question 9

What is the name of the layer of connective tissue that surrounds a bundle of muscle fibres?

Answer 9

perimysium

Question 10

Sarcomas of the blood vessels are known as…

Answer 10

angiosarcoma

Question 11

Sarcomas of muscle are known as…

Answer 11

rhabdomyosarcoma

Question 12

Sarcomas of the fat are known as…

Answer 12

liposarcoma

Question 13

what 2 places can osteochondritis occur?

Answer 13

femoral head and the medial femoral condyle of the knee

Question 14

The sarcomere is defined as the region from one _ ____ to the next

Answer 14

z disc

Question 15

benign bone tumours:

Tumour often occuring arround the knee and distal radius with a ‘soap bubble’ appearance

Answer 15

giant cell tumour

Question 16

benign bone tumours:

A tumour extensively involving the proximal femur with cortical thinning and a ‘Shepherd’s crook’ deformity.

Answer 16

fibrous dysplasia

Question 17

benign bone tumours:

A single lucent lesion, often an incidental finding, found most commonly within metaphyseal regions

Answer 17

simple bone cyst

Question 18

what are cells found in cartilage called?

Answer 18

chondrocytes

Question 19

what features are more reassuring of a malignant swelling?

Answer 19

> 5cm in size
irregular surface
systemic upset with weight loss and fatigue

Question 20

the cells responsible for the destruction of bone during remodelling are…

Answer 20

osteoclasts

Question 21

what is the most abundant component of cartilage extracellular matrix?

Answer 21

water

Question 22

soft tissue swellings:

a collection of pus which can be formed secondary to a penetrating wound

Answer 22

abscess

Question 23

soft tissue swellings:

Inflammation of the usually present, small fluid filled sac lined by synovium around joints which prevents friction between tendons, bones, muscle and skin. This inflammation commonly occurs after repeatedpressure or trauma and, therefore, may present as a soft tissue swelling.

Answer 23

bursitis

Question 24

soft tissue swellings:

A cystic swelling which occurs around a synovial joint or tendon sheath, as a result of herniation or out‐pouching of a weak portion of joint capsule or tendon sheath.

Answer 24

ganglion

Question 25

You are the orthopaedic reigistrar in the out-patient clinic. You are referred an 11 year old boy by his GP because he is concerned about a lump which has appeared on the outside of his thigh, just above his knee. The boy and his father tell you it has grown in size and they’re quite concerned. The lump itself is painless although it sometimes catches on the ilio-tibial band on the lateral aspect of his thigh. The boy is well, he doesn’t complain of any other symptoms and doesn’t have any significant past medical history. There is no family history of similar problems.

On examination, the boy is slim and you can feel a firm, bony lump on the lateral aspect of the distal femoral metaphysis. The skin and soft tissues overlying the lump are healthy. You do an x-ray and it shows a bony spur originating from the distal femoral metaphysis. The cortex is otherwise normal.

What is the diagnosis?

Answer 25

osteochondroma